Tag: silica glass

Speak about destruction. A comet slammed into Earth’s atmosphere 28 million years ago and basically killed everything with fire below, leaving a huge deposit of yellow silica glass in its wake, a team of astronomers say.

The evidence — a black pebble found by an Egyptian geologist within this vast tract of glass — is believed to be a part of the comet’s nucleus or heart and not just an ordinary meteorite. The team says this could be the first hard evidence, so to speak, of a comet striking Earth.

The temporary “shockwave of fire” hit 2,300 square miles (roughly 6,000 square kilometers) of Egyptian sand, turning the grains into glass. Given the area’s rich archaeological history, it’s probably not too much of a surprise that a small portion of this is visible in a brooch that belonged to ancient boy-king Tutankhamun.

A brooch that belonged to the Egyptian boy-king Tutankhamun, which reportedly contains a silica glass stone that originated from a comet explosion. Credit: University of the Witwatersrand, Johannesburg

“It’s a typical scientific euphoria when you eliminate all other options and come to the realization of what it must be,” said lead author Jan Kramers of the University of Johannesburg in a statement.

Besides silica, the cosmic blast furnace left teeny-tiny diamonds in its wake, forming from carbon. “Normally they form deep in the earth, where the pressure is high, but you can also generate very high pressure with shock. Part of the comet impacted and the shock of the impact produced the diamonds,” said Kramers.

More information on this find should be available soon when the discovery is published in Earth and Planetary Science Letters. The authors first discussed their find in a public lecture Oct. 10. It will be interesting to see what other scientific teams think of this hypothesis, so stay tuned for the reaction.